The present invention relates to high power gas lasers and more particularly to gas lasers of the type which are electron beam pumped and subjected to sustaining pulsing currents of the type described, for example, in U.S. Pat. No. 3,702,973.
High power laser structures of this general class have been built and operated in closed circuit (substantially closed circuit with some gas loss or deliberate bleed off and consequent need for limited make-up gas supply) modes as described for example in U.S. Pat. No. 3,921,098. The circulation of large amounts of gas under varying pressure and temperature conditions has been adapted to a substantial extent from closed circuit gas recirculation technology of wind tunnels and the like. The principal means for gas recirculation in the art are mechanical pumps such as fans or compressors which involves substantial weight, bulk and cost to the system and require energy.
It is an important object of the invention to enhance the economy and efficiency of gas laser apparatus.